Senior Software Engineer, Full Stack

Senior Software Engineer, Full Stack — Fintech San Francisco, CA On-Site

GPF Staffing is recruiting a Senior Full Stack Software Engineer for a rapidly growing, $100 million-funded fintech company building a next-generation neobank and merchant platform serving Mexico's underserved consumer and small-business markets.

This is an opportunity for an experienced, product-minded engineer to join as one of the first engineering hires in San Francisco. You'll have significant ownership over greenfield products, working across digital banking, merchant operations, payments, lending, and AI-powered consumer financial services.

The company is developing a comprehensive Merchant OS that integrates payroll, point-of-sale systems, inventory management, and financial services, alongside an AI-powered WhatsApp financial assistant designed to make banking more accessible.

You'll work closely with a small engineering and product team to build scalable financial technology products from the ground up while helping establish the technical foundation for the company's continued growth.

What You'll Do

• Build and own full-stack features end-to-end, from user interfaces and backend architecture through testing, deployment, and production.
• Design and develop scalable services supporting high transaction volumes across lending, payments, pay-ins, payouts, and financial ledger systems.
• Build core banking and merchant-facing applications designed to support thousands of small and medium-sized businesses.
• Develop a comprehensive Merchant OS, including payroll, point-of-sale, inventory tracking, and other essential business management tools.
• Build financial products integrated with a regulated Mexican banking platform.
• Contribute to the development of an AI-powered WhatsApp financial assistant that helps consumers access and manage financial services.
• Architect and optimize backend services, APIs, databases, and asynchronous processing systems for reliability and scalability.
• Help establish AI-assisted and agentic software development practices to accelerate the engineering lifecycle.
• Collaborate closely with product managers, designers, and engineers to translate business requirements into production-ready software.
• Take ownership of complex technical challenges and independently drive features from initial concept through delivery.
• Contribute to architectural decisions, engineering standards, and development practices as the San Francisco engineering team expands.

What We're Looking For

• 4–8+ years of professional software engineering experience, with a strong background in full-stack development.
• Demonstrated experience building and shipping production-grade applications across frontend and backend systems.
• Strong proficiency in TypeScript, React, Node.js, and modern full-stack JavaScript frameworks.
• Experience designing, developing, and maintaining scalable backend services and APIs.
• Strong understanding of SQL, relational databases, data modeling, and database performance.
• Experience working with message queuing systems and asynchronous processing.
• Ability to independently own complex features throughout the entire software development lifecycle.
• Experience building reliable, scalable systems that support growing user bases or significant transaction volumes.
• Strong product mindset and the ability to make technical decisions that balance engineering quality, user experience, and business objectives.
• Comfortable working in an early-stage environment with evolving requirements and significant individual ownership.
• Strong communication skills and the ability to collaborate effectively with cross-functional teams.
• Willingness to work on-site in San Francisco five days per week. Highly valued: Experience in fintech, digital banking, payments, lending, financial ledgers, or merchant software. Previous experience at an early-stage or high-growth startup, familiarity with regulated financial products, and experience using AI-assisted development tools are also valuable.

Technology Environment

TypeScript | React | Node.js | Full-Stack JavaScript Frameworks | SQL | Databases | Message Queuing Systems | AI-Assisted Development

Compensation

Base Salary: $180,000–$275,000

Equity: Competitive equity package

Location

San Francisco, CA

This is an on-site position requiring five days per week in the San Francisco office. Candidates who are not currently located in the Bay Area should be willing to relocate.

As one of the company's first San Francisco engineering hires, you'll have the opportunity to work closely with the founding engineering team and influence the technical direction of the platform.

Visa Eligibility

The company is open to considering eligible visa transfers, including qualifying H-1B transfers and OPT candidates.

Specific visa eligibility and sponsorship arrangements will be confirmed during the hiring process.

Hiring

The company is looking to hire 5 Senior Full Stack Software Engineers for its growing San Francisco engineering team.

This opportunity is particularly suited for a hands-on, product-minded full-stack engineer who enjoys building greenfield products and wants significant technical ownership in a well-funded, early-stage fintech. You'll work on complex financial technology challenges while helping develop banking and merchant solutions for an underserved market.